NEW YORK — Brooke Astor, the civic leader, philanthropist and high-society fixture who gave away nearly $200 million to support New York City’s great cultural institutions and a host of humbler projects, died Monday. She was 105.

Mrs. Astor, who recently was the center of a highly publicized legal dispute over her care, died of pneumonia at Holly Hill, her Westchester County estate, family lawyer Kenneth Warner said.

“Brooke was truly a remarkable woman and an irreplaceable friend,” longtime family friend David Rockefeller said. “She was the leading lady of New York in every sense of the word.”

Although a famous figure in New York City and feted with a fabulous gala on her 100th birthday in March 2002, Mrs. Astor was mostly interested in putting the fortune that husband Vincent Astor left to use helping others.

Her efforts won her a Presidential Medal of Freedom, the nation’s highest civilian honor, in 1998.

“Money is like manure, it should be spread around,” was her oft-quoted motto. There has been a lot to spread in the family ever since Vincent Astor’s great-great-grandfather, John Jacob Astor, made a fortune in fur trading and New York real estate.

Mrs. Astor gave millions to what she called the city’s “crown jewels” — among them the New York Public Library, Carnegie Hall, the Museum of Natural History, Central Park, the Bronx Zoo and the Metropolitan Museum of Art.

She also funded scores of smaller projects: Harlem’s Apollo Theater; a new boiler for a youth center; beachside bungalow preservation; a church pipe organ; furniture for homeless families moving in to apartments.

It was a very personal sort of philanthropy. “People just can’t come up here and say, ‘We’re doing something marvelous, send a check.’ We say, ‘Oh, yes, we’ll come and see it,’ ” she said.

The final year of Mrs. Astor’s life was marred by a family feud over her care, including allegations that she was forced to sleep on a couch that smelled of urine while subsisting on a diet of pureed peas and oatmeal.

Papers filed in July 2006 alleged she was being neglected, and in a settlement three months later her son, Anthony Marshall, was replaced as her legal guardian by Annette de la Renta, wife of the fashion designer Oscar de la Renta.

Marshall’s son Philip Marshall, a professor at Roger Williams University in Rhode Island, had alleged that his father was looting his grandmother’s estate and allowing her to live in filthy conditions at her Park Avenue duplex. Anthony Marshall, a former diplomat and sometime Broadway producer, denied any wrongdoing.

In December, a Manhattan judge ruled that claims “regarding Mrs. Astor’s medical and dental care, and the other allegations of intentional elder abuse” by Anthony Marshall were not substantiated.

“I have lost my beloved mother, and New York and the world have lost a great lady,” Anthony Marshall said. “She was one of a kind in every way.”

Mrs. Astor was born Brooke Russell in March 30, 1902.

She was the only child of John H. Russell, a career Marine officer who rose to become commandant of the Corps from 1934 to 1936. She was raised mostly overseas — China, Panama, Santo Domingo and Hawaii — as her father moved from posting to posting.

In 1953, she married Vincent Astor, the eldest son of John Jacob Astor IV, who died in the sinking of the Titanic. He was her third husband.

Vincent Astor, who had no children, died in 1959. He left his widow $2 million plus the interest off $60 million and endowed the Vincent Astor Foundation with an additional $67 million. It gave away approximately $200 million by the time it closed at the end of 1997.

Hers was a hands-on approach, personally going over applications and then going out to meet the people who ran the programs.

“Even in the worst drug areas, I don’t hesitate to go right in and see people,” she once said.

In addition to her son and grandson Philip, she is survived by another grandson, Alec.